1. Field of the Invention
The present invention relates to a railway signalling system and on-board signalling system which control railway trains and the like.
2. Description of the Related Art
In relation to such railway signalling systems, ERTMS/ETCS which is an integrated train control system intended to enable interoperability among European countries proposes a system requirements specification as described in “ERTMS/ETCS System Requirements Specification, Chapter 1 Introduction, 24.02.2006.” The system requirements specification stipulates, “Many different railway signalling systems have been developed so far, but they are incompatible with one another and do not allow interoperability. To reduce costs, it is desirable to introduce a standardized system.”
The conventional railway signalling system is made up of a dedicated trackside signalling system and a dedicated on-board signalling system, and a train cannot run unless it carries a dedicated on-board signalling system compliant with the railway signalling system of the line on which the train is to run. With such a railway signalling system, when running through into a line with a different signalling system, it is necessary to a carry an on-board signalling system compliant with the signalling system of each line and switch, at a boundary between lines, to the on-board signalling system used on the next line. This incurs high costs.
In contrast, if a common specification such as ERTMS/ETCS described in “ERTMS/ETCS System Requirements Specification, Chapter 1 Introduction, 24.02.2006” can be established for signalling systems, by simply carrying an on-board signalling system compliant with the common signalling system specification, trains can run through into lines which have adopted a signalling system with the common specification. However, in adopting such a common specification, it is difficult to adjust requested specifications among railway operators in charge of individual lines, complicating the specification in order to meet the requests of the individual railway operators, and thereby resulting in higher costs than conventional dedicated on-board signalling systems. Besides, the trackside signalling system on each line needs to comply with the common specification, incurring high update costs.
Thus, an object of the present invention is to provide a railway signalling system which enables running through into lines with different signalling systems using a single on-board signalling system.